Sync zoneinfo database with tzdata2015f from ftp://ftp.iana.org/tz/releases

Sync zoneinfo database with tzdata2015f from ftp://ftp.iana.org/tz/releases

* asia: North Korea switches to +0830 on 2015-08-15. (Thanks to
    Steffen Thorsen.) The abbreviation remains "KST". (Thanks to
    Robert Elz.)

* europe: Moldova starts and ends DST at 00:00 UTC, not at 01:00 UTC.
    (Thanks to Roman Tudos.) Also mention that Herbert Samuel
    introduced the term "Summer Time".

* northamerica: Comments for America/Halifax and America/Glace_Bay have
    been improved. (Thanks to Brian Inglis.)

* southamerica: Uruguay no longer observes DST. (Thanks to
    Steffen Thorsen and Pablo Camargo.)

* Theory: The Theory file mentions naming issues earlier, as these seem
    to be poorly publicized (thanks to Gilmore Davidson for reporting
    the problem).

* Various: Data entries have been simplified for Atlantic/Canary,
    Europe/Simferopol, Europe/Sofia, and Europe/Tallinn.  This yields
    slightly smaller installed data files for Europe/Simferopol and
    Europe/Tallinn. It does not affect timestamps. (Thanks to
    Howard Hinnant.)